1. Technical Field
The present disclosure relates to a wireless communication apparatus and method for transmitting IQ signals in a phased array system.
2. Description of the Related Art
A phased array system that performs directivity communication by using multiple antenna devices is attracting attention in various fields (for example, see RACZKOWSKI Kuba, et al., “A Wideband Beamformer for a Phased Array 60 GHz Receiver in 40 nm Digital CMOS”, Dig Tech Pap IEEE Int Solid State Circuits Conf, 2010, p. 36-38.). It may be possible enhance the communication efficiency by the application of IQ modulation to the phased array system.
However, quadrature errors, such as phase errors and amplitude errors, may occur between an in-phase signal (I signal) and a quadrature signal (Q signal) which form an IQ signal. In the case of the phased array system, such quadrature errors may occur in each of the multiple antenna devices.
An example of the technology for correcting IQ signals for quadrature errors is disclosed in International Publication No. 2011/121979. In this technology (hereinafter referred to as “the related art”), an IQ correcting circuit corrects two local (LO) signals out of phase with each other for quadrature errors so as to generate an I local signal and a Q local signal. Then, the generated I local signal and Q local signal are separately input into quadrature mixers disposed in two baseband signal systems.
By applying the related art to a phased array system, wireless communication using directivity-controlled IQ signals may be performed with reduced quadrature errors.